DE1109676B - Process for the preparation of haloalkylcyclopentenes - Google Patents

Description

Process for the preparation of haloalkylcyclopentenes The invention relates to the production of new cyclopentenyl haloalkanes by reacting a halocyclopentene with an aliphatic monoolefin in the presence of an alkylation catalyst known Friedel-Crafts catalyst.

It is known from US Pat. No. 2,562,369 that saturated Hydrocarbons in the presence of a catalyst containing chlorinated olefins Formation of chloroalkanes can be condensed.

It is also from Fieser and Fieser, Organic Chemistry, 3rd edition, S. 536, known that chloroalkanes reacted with olefins to form chloroalkanes can be. It is also known from US Pat. No. 2,481,160 that halogenated Cycloalkanes, e.g. B. chlorocyclopentane, with halogenated olefins, e.g. B. vinyl chloride, can be reacted so that polyhalogenated derivatives, e.g. B. dichloroethylcyclopentane, develop. In all of these reactions the end product is a saturated chloroalkane acyclic or cyclic nature.

It has now been found that haloalkylcyclopentenes in good yield can be obtained when halocyclopentene with an aliphatic monoolefin in the presence of a Friedel-Crafts catalyst known as an alkylation catalyst reacted.

The new compounds obtainable according to the invention are characterized by the following general formula: in which R represents a halogenated alkyl radical with 2 to 20 carbon atoms. R 'and R "denote hydrogen or alkyl radicals with 1 to 3 carbon atoms which are bonded to the ring, for example methyl or ethyl radicals. In the reaction according to the invention, the double bond in the halogenocyclopentene used as starting material is retained and is not attacked.

The products obtained according to the invention are extremely suitable good as chemical intermediates in the manufacture of valuable oxygenated Links. The products are also useful chemicals for agriculture. Chlorisobutylcyclopenten itself is well suited as a nematode killer or Soil fumigants.

The singly halogenated cyclopentene, z. B. 3- or 4-chlorocyclo- penten, find use. The expression "cyclopentene" includes mono- or dialkyl-substituted derivatives of these chlorocyclopentenes. The alkyl substituent should preferably have fewer than 8 carbon atoms; z. B. it can be a methyl, ethyl, Be propyl, butyl or pentyl radical. A typical alkyl substituted chlorocyclopentene is 3-chloro-4-ethylcyclopentene.

Obviously, other groups may also be present in other positions be. As noted earlier, the double bond remains in the reaction obtained, and the addition of the aliphatic monoolefin to the cyclopentene takes place to a single bonded or saturated carbon atom of the ring.

Apart from chlorinated derivatives, bromine or iodine derivatives can also be used so that the term "halogen" includes all three.

The aliphatic monoolefin can be an olefin having 2 to 20, preferably Use 2 to 8 carbon atoms per molecule with a straight or branched carbon chain. Examples of such monoolefins are ethylene, propylene, isopropylene, or butylene Isobutylene.

Any customary, generally known Friedel-Crafts catalyst, such as Fell3, Bs1 ,, All3, Al Br3, or BF3, are used. The amount of catalyst used is between 0.05 and 10 percent by weight, preferably between 0.1 and 5 percent by weight, based on the total load. If necessary, one can use conventional Diluents, e.g. B. heptane, hexane or carbon tetrachloride use.

The implementation is depending on the needs at atmospheric or elevated Pressure carried out. In the case of low-becoming olefins, e.g. B. ethylene or propylene In some cases it is better to work with a pressure that is sufficient to do this Keeping olefin in the liquid phase, although the implementation is also going smoothly goes when the light olefin is present as a gas. Press at an altitude of 105 atü can be used. The reaction takes place very quickly at temperatures from -50 to 1000 C; however, the temperature is preferably between -15 and + 10 ° C to keep.

One can determine the ratio of aliphatic olefin to halogenated Cyclopentene vary greatly from for example stoichiometric amounts up to preferably high excesses of aliphatic monoolefin, for example 2 to 10 mol aliphatic monoolefin or more moles per halocyclopentene can be used. In a batch operation, the halogenated cyclopentene becomes slow added to the aliphatic monoolefin in order to achieve the highly exothermic reaction To be able to regulate temperatures better. Continuous stirring during the addition and the subsequent reaction is advisable.

The process described above can easily be carried out batchwise, semi-continuously or carried out continuously by generally customary technical methods.

For a better understanding of the invention, reference is made to the following equation, which represents the implementation in question: In this reaction, 2 isomers are formed; However, the 3- (2-chloro-2-methylpropyl) -cyclopentene is the main product compared to the 4-substituted isomer.

The implementation can also proceed as follows: The chloroalkyl radical can also be bonded to carbon atom 4.

Reference is now made to the following examples illustrating the reaction and illustrate the resulting product.

Example 1 Into a flask were 181 g of isobutylene and 1 g of FeCl3 and the mixture was cooled to a temperature between -15 and 0 ° C. 142.5 g of chlorocyclopentene were added with stirring within 60 minutes, the temperature was kept between -15 and 0 ° C. After the chlorocyclopentene was completely added, the product was in vacuo at 15 mm of mercury distilled, and 140 g of cyclopentenylchlorobutane were obtained (a yield of 63.5 Mole percent, based on the chlorocyclopentene used).

The product had a density of 0.95 at 20 C and also at 20 ° C, a refractive index of 1.470.

This product was found to be a mixture of the 2 isomers listed in equation (1) above.

Example 2 The experiment of Example 1 was repeated using 360 g of isobutylene and 124 g of chlorocyclopentene at a temperature of about -5 "C used.

The reaction mixture was again distilled at 15 mm of mercury and obtained 140 g of the product or a 73 mole percent yield based on the chlorocyclopentene used. As in Example 1, the boiling point was between 63 and 71 "C at a pressure of 15 mm of mercury; the large boiling range is attributed to the presence of 2 isomers. At 20 "C the density was 0.95 and the refractive index 1.469. Analysis revealed a chlorine content of 22.25 percent by weight compared to a theoretical chlorine content of 22.35 Weight percent solid.

Example 3 In the repetition of Example 1, the olefin was used Propylene at atmospheric pressure. In this example, 300 cc of carbon tetrachloride was added in the Reaction flask and made sure the solvent was added 0 ° C and at atmospheric pressure was saturated with propylene and remained. To this mixture 124 g of chlorocyclopentene with 10 / o Fe Cla were added as a catalyst. The reaction temperature was 0 ° C and the addition extended over a period of 60 minutes. Man obtained an amount of product of 17.5 g, which corresponded to a yield of 10 mol percent. The boiling point of the product was 170 to 172 ° C at atmospheric pressure; the concentration was 0.96 and the refractive index was 1.464, measured at 20 "C. That determined by analysis Chlorine content was 24.25 percent by weight compared to a theoretical value of 24.51 percent by weight.

The results of the three examples just described and an additional experiment with butene- (I) are compiled in a table below. Attempt no. 1 2 3 1 4 Olefin used ................ Isobutylene Isobutylene Butene- (1) propylene Used catalyst ........... FeCl3 Fe Cl3 FeCl3 Fe Cl3 Loading, g Olefin ....................... 181 360 360 (a) Chlorocyclopentene ............. 142.5 124 124 124 Catalyst .................. 1.0 1.0 2.0 1.0 Reaction conditions Temperature, ° C .............. -15 to 0 -5 -5 to +5 0 Duration of the chlorocyclopentene addition, minutes .......... 60 60 60 60 Reaction product Won, g ................. 140 140 85 17.5 Yield, mole percent (d) 63.5 73 44.5 10 Boiling point, ° C at 15 mm Hg .. 63 to 71 (b) 63 to 71 (b) 78 to 87 (c) 170 to 172 (f) Density at 200C 0.95 0.95 0.97 0.96 Refractive index at 20 ° C ...... 1.470 1.469 1.473 1.464 Weight percent chlorine - 22.25 (e) 22.29 (e) 24.25 (g) (a) Reaction flask with 300 cm3 carbon tetrachloride which remained saturated with propylene at 0 ° C and atmospheric pressure.

(b) At air pressure (765 mm) 175 to 184 ° C with decomposition.

(c) At air pressure (765 mm) 190 to 205 "C.

(d) Based on chlorocyclopentene feed.

(e) Theoretically 22.35.

(f) Boiling point at atmospheric pressure (762 mm).

(g) Theoretically 24.61.

The values in this table indicate that one of the specified Conditions with isobutylene up to 73 0 / o Cyclopentenylchloralkane obtained.

The low yield from the propylene experiment was primarily due to attributed to the low concentration of propylene in the reaction flask.

You can increase the yield if you work under pressure, like this that the propylene is kept in the liquid phase and a sufficient propylene concentration is present in the reaction mixture. A comparison between experiment 1 and 2 in the The table shows that the yield can be increased if one with large surpluses working on aliphatic monoolefin. In Run 1 the ratio was aliphatic Monoolefin to chlorocyclopentene 2.3, while in Experiment 2 the ratio was 5.3.

The cyclopentenylhalogenoalkanes which can be prepared according to the invention are primarily suitable for the preparation of many new and useful derivatives. Cyclopentenylchloroisobutane, for example, can easily be oxidized to 2-oxyisobutylglutaric acid-y-lactone, as shown in the following equation: This lactone is particularly suitable for the production of polyester resins, which are suitable for the production of glass fiber laminates. The new compounds of the invention can also be dehydrochlorinated, so that new non-conjugated alkenylcyclopentenes are formed which are suitable for the production of resins and rubber-like copolymers.

Claims (2)

PATENT CLAIMS: 1. Process for the preparation of haloalkylcyclopentenes, characterized in that an aliphatic monoolefin having 2 to 20 carbon atoms with a halocyclopentene in the presence of what is known as an alkylation catalyst Friedel-Crafts catalyst at - 50 to 100 C and atmospheric or elevated pressure implements. 2. The method according to claim 1, characterized in that the monoolefinic Hydrocarbon in an amount of at least 2 moles per mole of halocyclopentene is admitted.